Following is a piece I wrote for the upcoming Homosassa River Alliance newsletter. I'm on the HRA Board of Directors. I'd welcome any comments/criticisms. It was a pleasure meeting you all at SWFWMD's Chassahowitzka boat ramp. Brad Rimbey
Homosassa & Chassahowitzka MFLs Revisited
Brad W. Rimbey
Florida law (373.042) requires Southwest Florida Water Management District (SWFWMD) to set Minimum Flows and Levels (MFLs) for all water bodies within the District. MFLs are intended to prevent “significant harm” to ecosystems via human related (anthropogenic) water uses. SWFWMD has adopted a policy which defines “significant harm” as any anthropogenic flow or water level reduction which causes a 15% loss of the affected ecosystem. The unilateral application of 15% harm as “significant harm” has repeatedly been questioned by SWFWMD's peer review panels.
Both Homosassa and Chassahowitzka were designated as Outstanding Florida Waters in 1993. Additionally, both of these coastal rivers were designated as Outstanding Florida Springs in 2016. These designations were intended to protect these waters from permanent degradation via anthropogenic activities. SWFWMD's current proposed MFLs continue to ignore these protective designations as they have opined a 15% degradation of these supposedly protected waters as acceptable.
In 2013, SWFWMD's Governing Board (GB) adopted MFLs which would allow only a 3% natural flow reduction for the Homosassa and Chassahowitzka Rivers. The Homosassa MFL was set at 3% based on predicted salinity changes in the Homosassa over 20 years. The Chassahowitzka MFL was based on maintaining a manatee thermal refuge at the eastern boundary of the Chassahowitzka National Wildlife Refuge. For Chassahowitzka, SWFWMD's GB rejected staff's MFL recommended 9% natural flow reduction and adopted a 3% flow reduction to match Homosassa's MFL. SWFWMD 's GB applied common sense over SWFWMD staff's “science based“ recommended MFLs.
In 2013, SWFWMD staff opined that approximately 1% of the natural flow had been taken from both the Homosassa and Chassahowitzka due to anthropogenic water extractions in these springs-sheds. SWFWMD's GB instructed staff to gather additional data to support their flow reduction recommendations within six years. Little has been done in that regard.
Six years have now passed and SWFWMD has released its draft peer review MFL reports. In the 2019 MFL peer review draft reports for Homosassa and Chassahowitzka, SWFWMD now opines that 1.9% of the natural flow has been taken from Homosassa and 1.4 % has been taken from Chassahowitzka. SWFWMD further predicts that only 3% of Homosassa's natural flow will be taken by 2035 and 2% will be taken from Chassahowitzka by 2035. Therefore, they conclude that no limit to future groundwater withdrawals from these spring-sheds is required for the next two decades.
The latest Homosassa and Chassahowitzka MFLs are focused on snook thermal refuge habitat. These water bodies are at northern range of snook habitat and snook could not exist here if not for the winter thermal refuge of our springs. If snook habitat is so important, how does it make sense to reduce spring flow via these MFLs? Are snook an endangered/threatened species like manatees?
As groundwater pumping and sea level rise continues to increase, the salinity of our spring-fed coastal rivers increases. Sea level rise is a worldwide occurrence and there is little we can do locally to avert this. However, we can and should do something to reduce groundwater pumping that adds to the destruction of our coastal springs.
SWFWMD's peer review panel is currently discussing the draft reports. These drafts can be be found on SWFWMD's website https://www.swfwmd.state.fl.us/projects/mfl/documents-and-reports . All SWFWMD documents on this matter are available to the public as required by Florida public records law. You can also follow the peer review conversation at https://swfwmd.discussion.community/?forum=708493 .